New evidence from UC San Francisco suggests the immune system’s most direct “hit squad” cells—CD8 killer T cells—may be reacting to Epstein-Barr virus (EBV) inside the brain’s fluid spaces in people with multiple sclerosis. It reveals a striking gap between what the blood shows and what the central nervous system seems to be quietly staging on its own. For years, the prevailing picture has been that MS is driven by a misdirected immune attack on myelin, with EBV viewed as an important risk signa

T-cells are a type of white blood cell that play a central role in the immune system’s response to cancer. They can recognize and eliminate cancer cells by detecting abnormal proteins (antigens) on the surface of these cells. Once a T-cell identifies a cancer cell, it becomes activated and releases toxic substances like perforin and granzymes to kill the target. Additionally, some T-cells, such as cytotoxic CD8 T-cells, are especially effective in directly attacking tumors. Cancer immunotherapie